Modeling the distribution of ideologies within US political parties

Abstract: Ideological polarization in Western democracies has accelerated in recent decades. Negative consequences include difficulty to make joint decisions for governance. Polarization studies have mostly focused on inter-group differences, as between US Democrats, Republicans and Independents. We address here ideological differences between liberal, conservatives, and moderates inside each political group. We ask whether changing internal group proportions can reduce or increase openness to engage with opposing groups. Research on polarization is hindered by social systems’ complexity. We use a “socio-physics” dynamic network model of interacting agents, able to contend with complexity difficulties. Using poll-derived parameters, we replicate the 1986-2025 yearly Gallup poll findings on the respective proportions of liberal, conservatives, and moderates among Democrats, Republicans and Independents. We analyze differences. We conjecture that factors such context and leadership may account for them. We explore their potential for altering the internal distribution of in-group identities to alleviate polarization.

Keywords: ideological polarization; opinion dynamics; statistical physics approaches for social dynamics